During operation, the track and slide rails of a snowmobile are cooled and lubricated by sprays of loose snow that are generated during the normal operation of the snowmobile on loose snow.
In snowmobiles having liquid cooled engines, heat exchangers are often provided under the tunnel to take advantage of these sprays of loose snow. The sprayed snow makes contact with the heat exchanger and absorbs the heat from the coolant flowing in the heat exchangers.
However, when a snowmobile operates on hard packed snow or an icy surface, smaller sprays are generated or no spray at all. As a result, the track and slide rails are not cooled as efficiently. Also, the friction between the track and slide rails increases since the amount of lubricant (i.e. snow) therebetween is reduced, which contributes to further heating of the track and slide rails and can lead to premature wear of these components. Also, in the case of snowmobiles with liquid cooled engines with heat exchangers provided under the tunnel, the coolant flowing in the heat exchangers is cooled less efficiently since the heat transfer then relies mostly on heat transfer with the cold air.
To address this problem, devices have been developed to scratch a surface of the ice or snow to generate a spray of ice or snow when the snowmobile operates on such surfaces in order to provide the desired cooling and lubrication. These devices are known by many different names such as snow tillers, spray generating devices, and snow lubrication devices. For simplicity, these will be referred to as ice scratchers herein.
U.S. Pat. No. 5,277,266, issued Jan. 22, 1994, the entirety of which is incorporated herein by reference describes one such device. The device consists of a rod forming a coil spring at one end thereof. The device is mounted on the snowmobile such that the end opposite the one where the coil spring is formed is in contact with the surface on which the snowmobile operates. The coil spring generates a downward force on the end contacting the surface, such that the end generates a spray of snow or ice as the snowmobile moves forward. The coil spring also allows the end contacting the surface to follow the surface which may not always be even.
Although the above device effectively generates a spray of snow or ice when the snowmobile moves forward, moving the snowmobile in the reverse direction with the end of the rod in contact with the surface on which the snowmobile operates can cause the rod to bend or even break.
Therefore, there is a need for an ice scratcher that can be used with the snowmobile moving forwardly or rearwardly.